Multiple reeved level luffing single hoist line for cranes and derricks



Sept. 24, 1957 o. MCLEAN 2,807,374

MULTIPLE REEVED LEVEL. LUFFING SINGLE HOIST LINE FOR CRANES AND DERRICKS 2 Sheets-Sheet 1 Filed Sept. 22, 1953 INVENTOR. LELANDQMCLEAM H V 3 mm Sept. 24, 1957 o. MCLEAN MULTIPLE REEVED LEVEL LUFFING SINGLE HOIST LINE FOR CRANES AND DERRICKS Filed Sept. 22, 1953 2 Sheets-Sheet 2 M MM. mo

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H15 A TTOE/VE Y U ed W8??? MULTIPLE ,REEVED LEVEL LUFFING SINGLE HOIST LINE FOR CRANES AND DERRICKS Leland McLean, Marion, Ohio, assignor of one-fourth to William D. Carothers, Crafton, Pa.

Application September 22, 1953, Serial No. 381,550

' 3 Claims. (Cl. 212-58) This invention relates to a crane construction of a type which is particularly adaptable to handling cargo to or from ships, and which maytherefore be termed a cargo crane.

While this crane may be mobile permitting to be moved fore and aft or thwartshimas may be desired to reach particular handling operations, this invention is illustrated mounted in a fixed position upon the deck of a ship. Also cranes of this invention may be mounted upon mobile carriers or in a fixed position for material handling on wharves, docks or other land installations.

Most prior art cranes or derricks have, employed a single hoist line leading over a boom point sheave, thence downwardly to load attaching means, which, when the boom is swung, results in a pendulum actionof the suspended load known in the art as slewing. Slewing of the load is caused by sudden starting or stopping of the swinging boom. When the boom is raised or lowered, the load swings toward and away from the boom which is referred to in the art as lufiing. Both of these pendulum actions are very objectionable.

To minimize pendulum action, cranes of the prior art have utilized independently controlled and spaced actuating load lines, converging from opposed directions and in dependently attached to the load. 'Theselines are either spaced laterally abo v'e the converged ends in a single boorn orrun from two laterally spaced b'ooms Anindependent-1y controlled winch is employed for each load line andthe load on the independently controlled load lines is balanced by manual control. When th'e brakes are applied to the two load line winches toprevent anyve'rtical movement "of the load, pendulum action is actually induced by the listing of the ship and the load is shifted from one line to the other of the laterally spaced suspension points in the. single boom point causing torsion in the boom which is objectionable... Pendulum actionrnay be induced while the boom is not brake application to the two winches that actuate the two load lines. .This type of crane requires twohois't winches, two .boom hoist winches, and four independent brake bands onthe wi nches. I V, H e

To overcome objectionable features of such cranes, it has been discovered that it is only necessary to utilize 'a single load hoist'line actuated by asingle winch with an enclosed or non-corrodingholding brake to prevent corrosion from salt air and water. The single load hoist line extends from the "drum to the gantry and then is reeved over sheaves in three parts between the top of a gantr'y mounted vertically above the hoomfoothinge pin, and

one side of the laterally spaced apart suspension points atone corner of the wide boom point, thence downwardly under a sheave in'the hookbl'ock, continuing upwardly over sheaves on the opposite side of the boom point corner, thence it is reeved in three parts to the gantry and is attached to a dead end at the top of the gantry. The load hoist line pulleys are positioned on the gantry and the boom at distances of a ratio of two feet up the gantry for each seven feet along the boom length. A gantry swinging by varying the having sheaves mounted twelve feet in height requires a boom having the load hoist sleeves forty-tw o feet from the boom hinge to accomplish level luffi'rig. When the hoist winch is held inactive and the boom raised or lowered, the load will travel in or out but will be maintained ina horizontal plane. This reeving of a single hoist line pref vents a pendulum action of the load in a plane at a right angle to the boom when slewing. A pendulum action in and out when the boom is raised or lowered isrednced but can be prevented by a ta gline mounted intermediate of the ends of the boom.

A further object of this invention is to provide a single winch with noncorrosive metal holding brake, to actuate a single boom hoist line reeved in two parts, to raise or lower only the weight of the boom regardless ofthe weight of the payload, as the entire weight of the payload is in compression within the boom.

Another object of this invention is to simplify the construction to the extent that the hoist machinery can be mounted within a ten foot circle upon a single deck,"

making it safer and less expensive to construct and main tain on account of its simplicity and the fact that at all times under all conditions the weight of the payload is equally divided upon each part of the two parts of the single hoist line suspending the load from the two opposite spaced apart boom point corners, preventing torsion of the boom. I V, v 7

Another object is the provision of new and useful iniprovements in material handling cranes whereby level lufiing can be accomplished by utilizing a two part line instead of a single line or two single lines which is equal to a single line in force applied to lifting the load, thus enabling this invention to lift twice as much per available horsepower as prior art cranes which utilize a single load line or the equivalent of a single line.

Other objects and advantages appear hereinafter in the following description and claims: I

Accompanying drawings show for the purpose of eirernplification, Without limitingthe invention or claims there- Fig. 6 is a side view of the operators station for operating the two winches, the slewing action and the winch brakes connecting means.

Refer-ring to ,Fig. l of the drawings, the supporting means 10 for the hoist is illustrated as a rigid portion of the ships structure. Various other types of supporting means may be employed, but generally it is desirable to mount aro'arg 'o crane upon th'ed'eck of the ship or above the level of the load to be handled by cranes embqdyfing this invention. the deck of the ship and series of four rollers 13 is rotatably mounted on the hook roller brackets -14. i

11 is underfrarne attached to The deck is is rotatably earned by the hook toil ts 13 of the crane. The deck carries the motor, machinery; booni, ganrry,'coatro1s"and operators station. The boom indicated at 16 is a box boom pivoted at 17 to the deck 15 and the gantry 18 is two-sevenths of the length of the boom and has the back legs 19. A motor 20 is energized by a generator mounted within the structure of the ship through suitable wiring and collector rings. The electric motor drives the hydraulic pumps 21 and 25 which energize the hydraulic motors 22 and 26 through suitable Patented Sept. 24, 1957 carries the circle gear 12. A

hoist winch 27 through the worm and wheels 24 and 28 respectively. V

. The hydraulic pumps also supply power through suitable piping and control valves at the operators station to energize the hydraulic motor 29 to drive the swinging or slewing action through the worm and worm wheel 30 to which, as illustrated in Fig. 6, is fixed a vertical swing shaft 31 and pinion 32 and which meshes with circle gear 12.

As shown in Fig. 6 the brake band 33 is made of noncorrosive metal as it is only a holding brake to prevent the load line from creeping due to leakage in the hydraulic motor after the motor has been stopped to stop the rotation of the winch 23 upon which the brake is applied. A similar boom hoist winch brake 34 is mounted on the boom hoist winch 27. These brakes are not used to'lower. the load or the boom as they are lowered by re versing the hydraulic motors through use of the control valves at the operators station.

The load hoist holding brake band 33 is applied by foot pedal 35 through conventional linkage and the boom hoist holding brake 34 is applied by pedal 36 through conventional linkage.

As shown in Fig. 6 a nest of hydraulic control valves with corresponding levers is indicated at 37 and the operators seat is shown at 38.

The boom hoist winch 27 has spooled about it one end of the boom hoist line 39 as shown in Fig. 2. The boom hoist line 39 extends from the winch 27 up over the right hand or far gantry sheave 40, thence forwardly around the two boom point suspension sheaves 41 and 42 back to dead end 43 at the opposite or left side at the top of the gantry. 44 indicates a spreader bar to properly space the sheaves 41 and 42 on their respective supporting brackets 45 and 45:: which oscillate about the boom point shaft 46 shown in Fig. 3.

The load hoist line 47 leads from its spooling upon the winch 23, being the left hand, up over the left gantry sheave 48, thence forward as, pass 47a and anticlockwise around the left hand or near boom point sheave 49, thence rearwardly as shown in Fig. 2 as pass 47b to sheave 51 clockwise around this sheave and forwardly as pass 47c and anticlockwise over the left hand fair-lead 52 suspended in the boom point and down :pass 47d and under hookblock sheave 53 journaled upon the axis in the hookblock 54, thence upwardly as pass 47:: clockwise over 'the right hand or far fair-lead 55, thence rearwardly on pass 47 and anticlockwise around gantry sheave 56, forwardly as pass 47g and anticlockwise around the right hand or far boom point sheave 57, rearwardly as pass 4711 to dead end 58 supported on shaft 59 at the top of gantry. 60, indicates a sleeve to stiffen shaft 59 and maintain proper spacing of gantry sheaves. The sheaves 49 and 57 are journaled on horizontal axis 46 between the brackets and 50a mounted on the boom point.

As shown in Figs. 1 and 4, 61 indicates a conventional springtension tagline mechanism with one end of a line 61a spooled about its drum and the other end attached to the eye 62 on the hookblock 54. The purpose is to prevent twisting of the hookblock and to prevent pendulum action in and out of the load when boom is raised or lowered. A non-corroding holding brake 63 controls the tagline drum in a conventional manner from the operators station.

64 indicates a cab enclosing the operators station and operating controls as shown in Fig. 1.

The sheave shaft 59 on the gantry 18 is mounted just above the boom pivot 17. As previously stated, the distance between the sheave shaft 59 and the boom pivot 17 is in the ratio of two-sevenths of the distance between the boom pivot 17 and the shaft 46 carrying the load, and the hoist line sheaves at the boom point. The purpose of this invention is to properly proportion these dimensions so that a suspended load will stay at the same elevation when the boom is raised and lowered. Theload hoist line will work through the sheaves as the boom goes up or down but the length is not changed and the load stays in the same horizontal plane. The boom point approaches the suspended load when it moves out and moves away from the load as it raises to move the load in.

While for clarity of explanation certain embodiments of this invention have been shown and described, it is to be understood that this invention is capable of many modifications and changes in the construction and arrangement of parts and certain parts may be employed without the conjoint use of other parts without departing from the spirit and scope of this invention.

I claim:

1. A rotatably mounted crane comprising a foundation, a deck, a gantry mounted on the deck, a boom pivotally mounted on the deck, two pairs of sheaves laterally spaced apart journaled on a horizontal axis mounted in the top of the gantry directly above the boom pivotal connection to the deck at a distance equal to two-sevenths of the distance between the boom pivotal connection to the deck and the boom point mounted axis upon which two spaced apart sheaves are journaled, two spaced apart fairleads suspended in the boom point, their axis being the same distance from the boom foot pivoted connection as the said axis of the boom point sheaves, two spaced apart sheaves journaled in a bridle pivotally attached to the boom point, two single winches, a hoist line having one end wound around one of said winches and having its intermediate portion reeved in three parts between one pair of the spaced apart pairs of gantry sheaves, and one of the spaced apart boom point sheaves and fair-lead, in two parts between the boom point fair-leads and the sheave of the load engaging means, and in three parts between the opposite boom point fair-lead and sheave and one of the opposite pairs of sheaves on the gantry and the dead end attached to the gantry, a boom hoist line having one end wound about the other of said winches and extending over a gantry sheave, thence around the said bridle sheaves to a dead end on the gantry, the said reeving of said-hoist line about the said sheaves and fairleads substantially providing for levellufiing with two parts of a single hoist line reeved between boom point and load engaging means.

2. The structure of claim 1 characterized by the winches being held against drifting by means of non-corrosive holding brakes.

3. The structure of claim 1 characterized by a controllable spring tension tagline mounted intermediate of the ends of the boom with one end wound around the tagline drum and the other end attached tothe load engaging means.

References Cited in the file of this patent UNITED STATES PATENTS 1,111,102 Sawyer Sept. 22, 1914 1,437,685 Scharpenberg et al. Dec. 5, 1922 2,355,235 Nickles Aug. 8, 1944 2,419,209 r Goodman et al Apr. 22, 1947 2,601,611 Hilborn et al. June 24, 1952 2,627,984 Senn et a1 Feb. 10, 1953 

